Modified polyacrylamide-supported chlorochromate as a new polymeric oxidizing agent

Article abstract of DOI:10.2298/JSC110131216T

Modified polyacrylamide-supported chlorochromate was synthesized and used as a versatile and efficient oxidizing agent for the oxidation of various organic compounds, such as hydroxyl compounds, silylethers, oximes, thiols, and others. Over oxidation of the products (aldehydes to carboxylic acids) was not observed with this oxidizing agent. The oxidant was insoluble in the oxidation media and the chromium(VI) ions remained firmly bound to the insoluble polymeric support after the oxidation reaction. The mild reaction condition, easy work-up, short reaction times, regenerability of the reagent and its easy preparation and handling are among the advantages of this new polymeric chlorochromate reagent. 2012 Copyright (CC) SCS.

Full text of DOI:10.2298/JSC110131216T

J. Serb. Chem. Soc. 77 (5) 685–697 (2012)
JSCS–4300
UDC 678.744.32’327+546.766+
546.13:66.095.2.094.3
Original scientific paper
Modified polyacrylamide-supported chlorochromate
as a new polymeric oxidizing agent
*
BAHMAN TAMAMI , ROGHAYEH HEIRAN and ELHAM RIAZI MONTAZER
Department of Chemistry, Shiraz University, Shiraz-71454, Iran
(Received 31 January, revised 21 December 2011)
Abstract: Modified polyacrylamide-supported chlorochromate was synthesized
and used as a versatile and efficient oxidizing agent for the oxidation of various
organic compounds, such as hydroxyl compounds, silylethers, oximes, thiols,
and others. Over oxidation of the products (aldehydes to carboxylic acids) was
not observed with this oxidizing agent. The oxidant was insoluble in the oxi-
dation media and the chromium(VI) ions remained firmly bound to the inso-
luble polymeric support after the oxidation reaction. The mild reaction con-
dition, easy work-up, short reaction times, regenerability of the reagent and its
easy preparation and handling are among the advantages of this new polymeric
chlorochromate reagent.
Keywords: chromium(VI) oxidant; modified polyacrylamide; polymeric oxi-
dizing agent; chlorochromate.
INTRODUCTION
During the past years, there have been several important advances in the
1
field of organic synthesis; the use of polymer-supported reagents is one of them.
Polymeric reagents can be defined as functionalized polymers used in stoichio-
metric amounts in one-step processes to transform low-molecular-weight substra-
2
tes into products. They have been investigated widely and a very large range of
3
reactions can be realized using such reagents. The most important benefits of
these reagents over their soluble counterparts are simple filtration procedures, ease
4
of separation from the reaction mixture, selectivity and low toxicity. These rea-
gents have been developed for use in simple reactions, such as oxidation, reduc-
5
tion, condensation, acylation, alkylation, halogenation, the Wittig reaction, etc.
Chromium(VI)-based oxidizing reagents have been extensively used in orga-
6
7
nic synthesis. Among these, pyridinium chlorochromate (PCC), prolinium
8
9
chlorochromate, caffenilium chlorochromate, tetrahexylammonium chlorochro-
*Corresponding author. E-mail: tamami@chem.susc.ac.ir
doi: 10.2298/JSC110131216T
685
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TAMAMI, HEIRAN and MONTAZER
10
11,12
mate, 2,6-dicarboxypyridinium chlorochromate,
and tributylammonium
13
chlorochromate are a number of oxidizing agents based on chlorochromate that
have been reported.
Numerous heterogeneous polymer-supported oxidizing agents with different
functionalities have been reported in the literature that offers some advantages
over their more traditional soluble counterparts. Among these, polymer-bound
metallic oxidants and especially polymer-supported chromium(VI) reagents have
14
received considerable attention. Heterogeneous polymeric reagents such as po-
15,16
ly[vinyl(pyridinium chlorochromate)] and dichromate,
poly(n-butyl-4-vinyl-
17
18
pyridinium)dichromate, poly(4-vinylpyridinium nitrate), poly(N-vinylpyrroli-
19
done)-hydrotribromide, poly(n-butyl-4-vinylpyridinium)periodate, iodate and
bromate, polystyrene supported t-butylchromates and poly[vinyl (pyrolido-
nium chlorochromates)] are among those reported in the literature.
20
21
22
23–26
In continuation of our interest on modified polyacrylamides,
the syn-
thesis and use of a modified polyacrylamide-supported chlorochromate as new
polymeric oxidizing agent for the oxidation of various organic compounds, such
as hydroxyl compounds, oximes, silylethers, thiols and some other compounds,
are described herein.
EXPERIMENTAL
Chemicals were purchased either from Merck or Fluka, or were synthesized in the la-
boratory. Acrylamide and the cross-linking agent, N,N’-methylene bisacrylamide (NNMBA),
were commercial products obtained from Merck. Trimethylsilyl ethers were prepared by a
1
reported procedure.27 All products were characterized by comparison of their IR and/or H-
-NMR spectra and physical data with those of authentic samples. All yields refer to the
isolated products.
The purity determination of the substrates and products and monitoring of the reaction
were accomplished by thin layer chromatography (TLC) on silica gel polygram SIL/UV 254
1
plates. The FTIR spectra were run on a Shimadzu FTIR-8300 spectrophotometer. The H-
-NMR (250 MHz) and 13C-NMR (62.5 MHz) were recorded on a Bruker Advanced DPX
instrument. Melting points were recorded on a Büchi B-545 apparatus (Switzerland) in open
capillary tubes.
Preparation of different cross-linked polyacrylamides (I)
Cross-linked polyacrylamide (Scheme 1) was synthesized by the free-radical precipita-
tion polymerization technique using N,N’-methylene bisacrylamide (NNMBA) as a cross-link-
ing agent.26,28 As an example for the preparation of 5 % cross-linked polyacrylamide, acryl-
amide (5.00 g, 69.0 mmol) and (NNMBA) (0.56 g, 3.6 mmol) were dissolved in ethanol (40
mL). Potassium persulfate (0.017 g, 0.070 mmol) was added as an initiator and the mixture
was heated at 75–80 °C under stirring for 7 h. The polymer was collected by filtration, washed
several times with ethanol and dried under vacuum at 50 °C. A white powder was obtained in
almost quantitative yield. The same procedure was repeated for the preparation of 2, 10, 15
and 20 % cross-linked polyacrylamides using 0.22, 1.18, 1.85 and 2.66 g of NNMBA, res-
pectively.
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POLYACRYLAMIDE-SUPPORTED CHLOROCHROMATE AS NEW OXIDIZING AGENT
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Scheme 1. Cross-linked polyacrylamide synthesis route.
Incorporation of (3-diethylamino-1-propylamine) function onto cross-linked polyacrylamide
In a round bottomed flask, excess 3-diethylamino-1-propylamine (35 mL) was added to 5 %
cross-linked polyacrylamide (I) (5.00 g). The reaction mixture was stirred at room tem-
perature to allow complete swelling of the polymer by the diamine. The reaction mixture was
then heated at 100 °C for 5 h. The aminated gel was filtered and washed with sodium chloride
solution (0.1 M) many times; it was then washed with water and ethanol. The product was
dried under vacuum at 60 °C to give the aminated resin (II) in 42 % yield (7.25 g).
Incorporation of chlorochromate function onto the aminated cross-linked polymer
In a round bottomed flask, chromium trioxide (4.50 g, 45.0 mmol,) was added to ami-
nated cross-linked polymer (II) (5.00 g) suspended in HCl (50 mL, 1 M). The mixture was
stirred in an ice bath for 4 h and filtered. The brown beads were filtered off and washed
extensively with acetone until the filtrate was clear. The resin was then dried under vacuum
(60 °C, 5 h) in the presence of CaCl2 to give a stable brown powder (III). The capacity of this
resin was determined by the iodometric titration method to be 1.64 mmol CrO3 g-1 polymeric
reagent, which was in agreement with the value of 1.58 obtained by the atomic absorption
technique.29
Determination of capacity of 5 % cross-linked polymer (III) by atomic absorption technique
A series of standards containing 0.00, 0.90, 1.50, 3.00, 4.50, 6.00, 7.50, 9.00 ppm of
CrO3 (with respect to Cr) were prepared in water and their atomic absorptions were de-
termined (Fig. 1). To a solution of potassium hydroxide (0.40 g) in water (10 mL) was added
polymeric reagent (III) (0.08 g), which was then stirred for 12 h. The mixture was filtered and
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TAMAMI, HEIRAN and MONTAZER
washed with distilled water several times. Activated carbon black was added to the combined
filtrates and the mixture was stirred for 20 min at 40 °C. Then, the mixture was filtered and
washed with distilled water. The solution of the combined filtrates was diluted to 500 mL in a
volumetric flask; then 10 mL of this solution was diluted to 250 mL. Atomic absorption
spectroscopy of the final solution with respect to chromium gave an absorbance value of
1.014 using the calibration curve (Fig. 1). The capacity of the reagent was determined to be
1.58 mmol of CrO3 per gram of the reagent.
Fig. 1. Calibration curve for the ato-
mic absorption spectroscopy method.
General procedure for the oxidation of organic compounds with the
5 % cross-linked polymer (III)
In a round bottomed flask (25 mL), a mixture of the organic compound (1.00 mmol) and
polymeric reagent (III) (2.00–4.00 mmol, based on the molar ratio of oxidant to substrate) in
cyclohexane or n-hexane (10 mL) was stirred at room temperature for an appropriate time.
The progress of the reaction was followed by TLC. When the reaction was completed, the
resin was filtered off and washed twice with solvent. Evaporation of the combined filtrates
afforded pure products (in the few cases when the reaction did not go to completion, the crude
product was purified on a silica gel plate with an appropriate eluent).
Regeneration of the 5 % cross-linked polymer (III)
The spent polymeric reagents obtained from different oxidation reactions were combined
and washed thoroughly with CH2Cl2 to remove any residual soluble organic substrate or
product; then it was washed with HCl (1 M) until the filtrate was colorless, neutralized with
NaOH (1 M), washed with water and acetone and finally vacuum dried. The polymer (10.00
g) was suspended in HCl (100 mL, 1 M) for 0.5–1.0 h, chromium trioxide (9.00 g) added and
the mixture stirred for 4.0 h at 0 °C. It was filtered and washed with acetone until the filtrate
was clear. The obtained polymer was dried under vacuum (50 °C) in the presence of CaCl2
overnight. The capacities of the regenerated resins were determined as described previously.
RESULTS AND DISCUSSION
Copolymers of acrylamide with NNMBA as a cross-linking agent (2, 5, 10,
15 and 20 %) were prepared by free-radical precipitation polymerization using
potassium persulfate as the initiator (Scheme 1). White polymers were obtained
as irregularly-shaped amorphous particles. The IR spectra of the polymers showed
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POLYACRYLAMIDE-SUPPORTED CHLOROCHROMATE AS NEW OXIDIZING AGENT
689
characteristic absorptions of amide (N–H), and carbonyl groups at 3421 and 1666
–1
cm , respectively (Fig. 2).
Fig. 2. FTIR spectrum of I.
Poly[N-3-(diethylamino)propyl] acrylamides (II) with different degrees of
cross-linking were prepared by transamidation reaction of excess 3-diethylamino-
-1-propylamine with the polyacrylamides having different degrees of cross-link-
ing (Scheme 1). The amino polymer exhibited strong absorption bands at 3202
–1
–1
and 3329 cm (N–H stretching), 1655 cm (C=O amide stretching) and 1528
–1
cm (N–H amide bending) (Fig. 3). The average amine value (4.70 mmol amine
–1
g
of polymer) was calculated by the back acid–base titration method. It was
noticed that as the proportion of the cross linking agent increased, the capacity of
the polymer decreased because of the highly cross-linked network structure.
Fig. 3. FTIR spectrum of II.
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TAMAMI, HEIRAN and MONTAZER
Polymeric oxidizing agents containing chlorochromate (III) were prepared
very easily by addition of chromium(VI) oxide to a suspension of the cross-linked
poly[N-3-(diethylamino)propyl] acrylamides in dilute HCl (Scheme 1). The pre-
sence of the chlorochromate anion in the oxidizing agents was confirmed by their
–1
IR spectra, showing bands at 945 and 769 cm , which are characteristic peaks
for the chromate anion (Fig. 4). Capacity of the polymeric oxidizing agent (5 %
cross-linked) was measured easily by titration with an appropriate reducing agent
2–
(S O ) and by atomic absorption spectroscopy. The obtained values were 1.64
2
3
–1
and 1.58 mmol Cr(VI) g polymeric reagent, respectively.
Fig. 4. FTIR spectrum of III.
As a model, the oxidation reaction of benzyl alcohol with the polymeric
reagents having different percentage crosslinking was performed in cyclohexane
at room temperature (Table I). The best results were obtained using the gel-like 2 %
cross-linked polymer, which was difficult to handle however; thus the 5 % cross-
-linked sample was chosen for the general study, due to its better stability.
TABLE I. Oxidation of benzyl alcohol with polymer III of different degrees of cross-linking
in cyclohexane (molar ratio of polymeric oxidant to substrate was 2:1; wet polymer was used;
conversion in all cases was 100 %)
Content of III in polymer
Average capacity of polymer
mmol g-1
Entry
Time, h
%
1
2
3
4
5
2
5
10
15
20
1.80
1.64
1.10
1.04
0.81
2.5
3.0
4.0
4.5
5.0
The choice of solvent in organic reactions using polymeric reagents is extre-
mely important. A solvent should be chosen in which the insoluble polymeric
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POLYACRYLAMIDE-SUPPORTED CHLOROCHROMATE AS NEW OXIDIZING AGENT
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oxidizing agent swells well. The effect of solvent on the oxidation reaction
showed that less polar solvents gave the best results. For the oxidation reaction,
cyclohexane and n-hexane were the best solvents compared to toluene, ethyl
acetate, CH CN, THF, CHCl and H O. This is probably due to the higher com-
3
3
2
patibility of these two solvents with the polymeric reagent and the substrates. The
polymeric oxidant was insoluble in the reaction media and the chromium ions
remained firmly bound to the insoluble polymer support after the oxidation reac-
tion, which was confirmed by atomic absorption spectroscopy (chromium ions
were not observed in reaction solvent after filtration). This advantage is one of
the advantages of this polymeric reagent over monomeric chromium(VI)-based
oxidants.
The generality of this polymeric oxidant was tested for different alcohols
(Table II) and other functionalities (Table III). The oxidant was capable to con-
vert primary and secondary alcohols to their corresponding aldehydes and keto-
nes. Over-oxidation of the products to carboxylic acids was not observed. Elec-
tron donating groups increased the rate of conversion. Aliphatic alcohols had a
low yield so the oxidant could oxidize selectively benzylic alcohols in the pre-
sence of aliphatic alcohols.
TABLE II. Oxidation of benzylic alcohols with 5 % cross-linked polymer III (these reactions
were carried out in cyclohexane at r.t.; wet polymer was used; molar ratio of polymeric
oxidant to substrate was 2:1)
Entry
1
Substrate
CH2OH
CH2OH
Product
CHO
CHO
Time, h Yield, %
3
6
6
90
80
70
2
3
Cl
Cl
Cl
CH2OH
NO2
CH2OH
Cl
CHO
NO2
4
5
10
4
45
90
CH2OH
MeO
MeO
CH2OH
CHO
OMe
CH2OH
CH2OH
6
7
4
4
85
92
OMe
CHO
MeO
MeO
CHO
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TAMAMI, HEIRAN and MONTAZER
TABLE II. Continued
Entry
Substrate
Product
Time, h Yield, %
Me
Me
8
9
5.5
5
85
92
CHO
OH
CHO
CH2OH
OH
CH2OH
10
11
5
95
80
85
CHO
CHO
CH2OH
OH
O
O
12
20
Ph
Ph
12
OH
OH
CHO
CHO
13
14
10
40
90
O
OH
3.5
O
OH
CH3
15
3
3
95
93
CH3
16a
OH
CHO
OH
Molar ratio of polymeric oxidant to substrate was 3:1
a
Aldoximes, ketoximes, and silylethers were oxidized to their corresponding
aldehydes and ketones without over-oxidation in good to high yields. Deoxima-
tion of oximes required a long reaction time compared to the oxidation of alco-
hols. The oxidation of thiols to their corresponding disulfides was performed
easily by this polymeric reagent. The oxidation of p-hydroquinone, benzylamine,
and benzoin were also investigated.
The oxidant was not able to oxidize α-hydroxyl carboxylic acids, toluene,
naphthalene, epoxides and sulfides. Hence, hydroxyl compounds, oximes, silyl-
ethers and thiols can be selectively oxidized in the presence of these functional
groups.
Regenerability and reuse of the spent polymeric reagent is one of the main
advantages in the use of this polymeric reagent. The reagent could be recycled at
least three times (Table IV). There was a small decrease in the capacity of the
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POLYACRYLAMIDE-SUPPORTED CHLOROCHROMATE AS NEW OXIDIZING AGENT
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resins after each regeneration, which might have been caused by mechanical de-
22
gradation of the polymeric reagent. This polymeric reagent can be stored seve-
ral months without loss of its activity.
TABLE III. Oxidation of other organic compounds with 5 % cross-linked polymer (III); these
reactions were realized in cyclohexane at room temperature; wet polymer was used
Entry
1a
Substrate
Product
Time, h Yield, %
OSi(Me)3
4.5
4.0
4.5
93
90
82
CHO
OSi(Me)3
2a
3a
MeO
CHO
MeO
OMe
OMe
CHO
OSi(Me)3
MeO
MeO
5.5
7.0
95
90
OSi(Me)3
4a
CHO
Cl
Cl
OSi(Me)3
OSi(Me)3
5a
6a
7a
CHO
7.0
5.0
93
90
Cl
CHO
Cl
Me
OH
Me
OH
OSi(Me)3
OSi(Me)3
CHO
6.0
5.0
85
73
8a
9a
CHO
O
OSi(Me)3
Me
Me
O
OSi(Me)3
5.0
78
10a
10.0
8.0
90
75
H
11b
12b
C NOH
CHO
CHO
H
MeO
NOH
C
MeO
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TAMAMI, HEIRAN and MONTAZER
TABLE III. Continued
Entry
Substrate
Product
Time, h Yield, %
OMe
OMe
9.0
78
13b
CHO
C
H
NOH
Me
Me
11.0
75
14b
CHO
C
NOH
H
10.0
8.0
82
95
40
15b
16b
Me
C NOH
Me
CHO
H
HO
CHO
CHO
HO
C NOH
H
10.0
O2N
C NOH
17b
18b
19b
20b
21c
O2N
H
O
NOH
10.0
90
C Me
Me
O
NOH
9.0
90
70
Me
HO
Me
C Me
Me
O
NOH
C Me
12.0
HO
Me
5.0
1.0
85
95
S
SH
SH
O
2
O
S
22c
23c
2
)
5/6
9.0
92
50
Me
Me
HS
HO
SH
Me
S
2
(
SH
)
S
)
6
(
)
6
24d
25d
26a
Me
2
S )
9.0
10
96
HO
O
OH
2
45/60
OH
O
8.0
5.0
60
75
27a
O
O
O
OH
NH2
CHO
28a
a
b
Molar ratio of polymeric oxidant to substrate was 2:1; Molar ratio of polymeric oxidant to substrate was 4:1
c
d
and reactions were realized in n-hexane at r.t.; Molar ratio of polymeric oxidant to substrate was 3:1;
%
conversion and molar ratio of polymeric oxidant to substrate was 3:1
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POLYACRYLAMIDE-SUPPORTED CHLOROCHROMATE AS NEW OXIDIZING AGENT
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TABLE IV. Capacity of the polymeric reagent after regeneration
Number of regenerations
Capacity of polymer, mmol g-1
1
2
3
1.30
1.15
0.92
A comparison of the efficiency of the presented polymeric reagent (III) with
a number of other reported polymeric oxidants based on chromium(VI) is given
in Table V. The polymeric reagent (III) is more efficient in the oxidation of
1-phenylethanol than most of the other reagents.
TABLE V. Comparison of the efficiency of III with those of different chromium(VI)-based
polymeric oxidants in the oxidation of 1-phenylethanol
Entry
Oxidizing agent
Time, h
Molar ratio
2/1 (r.t)
4.5/1 (reflux)
1.1/1 (reflux)
1.1/1 (reflux)
2/1 (reflux)
5/1 (reflux)
Yield, %
1a
III
ref. 15
ref. 16
3
3.5
5
24
12.5
44
95
69d
89d
>99d
91
2a
3a
4a
5b
ref. 17
ref. 22
ref. 30
96
95
6c
25/60
1/1 (reflux)
a
b
c
Reactions were realized in cyclohexane; reaction was realized in chloroform; reaction was realized in tolue-
d
ne; % conversion
CONCLUSIONS
In conclusion, this modified polyacrylamide-supported chlorochromate is a
useful oxidant for the oxidation of different organic compounds, such as hyd-
roxyl compounds, silylethers, oximes, thiols, etc. Over oxidation of the products
was not observed with this oxidizing agent. It was able to oxidize the aforemen-
tioned functional groups in the presence of α–hydroxyacids, benzylic acids, epo-
xides, sulfides, aldehydes and double bonds. The handling and use of this hetero-
geneous reagent is environmentally safer than its monomeric soluble counter-
parts. The mild reaction conditions, stability, selectivity, good to excellent yields
of the products, simple recovery of the reaction products and regenerability of the
reagent make this heterogeneous polymeric oxidizing agent useful in organic
synthesis. The reagent can be stored for months without any loss in its activity.
Acknowledgments. We gratefully acknowledge the partial supported of this study by the
Shiraz University Research Council.
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TAMAMI, HEIRAN and MONTAZER
И З В О Д
ПОЛИАКРИЛАМИД МОДИФИКОВАН ДИЕТИЛПРОПИЛАМОНИЈУМ-ХЛОР-
ХРОМАТОМ – НОВИ ПОЛИМЕРНИ ОКСИДАЦИОНИ АГЕНС
BAHMAN TAMAMI, ROGHAYE HEIRAN и ELHAM RIAZI MONTAZER
Department of Chemistry, Shiraz University, Shiraz-71454, Iran
Полимерни носач, на бази умреженог полиакриламида, модификован диетилпропил-
амонијум-хлорхроматом, показао се као веома ефикасан реагенс за оксидацију различитих
органских једињења: алкохола, силилетра, оксима, тиола, итд. У реакцијама оксидације ал-
кохола, производи оксидације су били алдехиди или кетони, и није се одвијала даља окси-
дација алдехида у карбоксилне киселине. Оксидациони агенс је нерастворан у реакционој
средини, а хром(VI) јони остају везани за полимерну матрицу и након реакције оксидације.
Предности овог новог полимерног оксидационог реагенса, диетилпропиламонијум-хлорхро-
мата, су: благи реакциони услови, једноставан начин и кратко време извођења реакције ок-
сидације, као и једноставна и лака регенерација реагенса.
(Примљено 31. јануара, ревидирано 21. децембра 2011)
REFERENCES
1. A. McKillop, D. W. Young, Synthesis 1979 (1979) 401
2. A. Akelah, A. Moet, Functionalized Polymers and their Applications, Thomson Press
India, New Delhi, 1990, p. 79
3. D. C. Sherington, P. Hodge, Synthesis and Separation Using Functional Polymers, Wiley,
New York, 1988, p. 45
4. A. Akelah, D. C. Sherington, Chem. Rev. 81 (1981) 557
5. D. C. Sherington, P. Hodge, Synthesis and Separation Using Functional Polymers, Wiley,
New York, 1988, p. 75
6. W. J. Mijs, C. R. H. I. de Jonge, Organic Synthesis by Oxidation with Metal Compounds,
Plenum Press, New York, 1986, p.119
7. G. Buchi, B. Egger, J. Org. Chem. 36 (1971) 2021
8. M. Mamaghani, F. Shirini, F. Parsa, Russ. J. Org. Chem. 38 (2002) 1113
9. F. Shirini, I. Mohammadpoor-Baltork, Z. Hejazi, P. Heravi, Bull. Korean Chem. Soc. 24
(2003) 517
10. B. Koohestani, Z. Javanshir, S. H. Ghammamy, K. H. Mehrani, H. Afrand, L. Saghat-
foroush, J. Mex. Chem. Soc. 52 (2008) 116
11. M. Tajbakhsh, R. Hosseinzadeh, M. Yazdani-Niaki, J. Chem. Res. 2002 (2002) 508
12. R. Hosseinzadeh, M. Tajbakhsh, M. Yazdani-Niaki, Tetrahedron Lett. 43 (2002) 9413
13. S. H. Ghammamy, M. Mazareey, J. Serb. Chem. Soc. 70 (2005) 687
14. D. H. Drewry, D. M. Coe, S. Poon, Med. Res. Rev. 19 (1999) 97
15. J. M. J. Frechet, J. Warnock, M. J. Farral, J. Org. Chem. 43 (1978) 2618
16. J. M. J. Frechet, P. Darling, M. J. Farral, J. Org. Chem. 46 (1981) 1728
17. B. Tamami, A. R. Kiasat, Iran. Polym. J. 6 (1997) 273
18. A. Ghorbani-Choghamarani, S. Sardari, J. Sulfur Chem. 32 (2011) 63
19. E. P. Koshy, J. Zacharias, V. N. R. Pillai, React. Funct. Polym. 66 (2006) 845
20. B. Tamami, K. Parvanak-Borujeny, M. M. Khakzad, Iran. Polym. J. 12 (2003) 4, 331
21. K. Geethakumari, K. Sreekumar, React. Funct. Polym. 42 (1999) 11
22. J. Zacharias, E. P. Koshy, V. N. R. Pillai, React. Funct. Polym. 56 (2003) 159
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23. B. Tamami, H. Mahdavi, Tetrahedron Lett. 42 (2001) 8721
24. B. Tamami, M. Kolahdoozan, Tetrahedron Lett. 42 (2004) 1535
25. B. Tamami, A. Fadavi, Catal. Commun. 6 (2005) 747
26. B. Tamami, S. Ghasemi, J. Iran. Chem. Soc. 5 (2008) S26
27. B. Karimi, B. Golshani, J. Org. Chem. 65 (2000) 7228
28. B. Tamami, S. Ghasemi, Appl. Catal., A 393 (2011) 242
29. D. A. Skoog, D. M. West, Fundamentals of Analytical Chemistry, 4th ed., Saunders
College, Philadelphia, PA, 1982, p. 582
30. B. Tamami, N. Goudarzian, Eur. Polym. J. 28 (1992) 1035.
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